Dang! I am still having this problem with the liner and how it has those seams. Wears fine for about 1 1/2 hours then the headache starts in. This is the mark I have when I take off the helmet. It's deeper than it looks in this photo. I'm not sure what to do at this point. I have done several rides and this is still the only problem I have with the helmet.

Carefully take a spoon and work the foam down in that precise area behind the seam.
It worked for me, I found mine was just a little tight on the forehead area.
Repeated working with the back side if the spoon made the helmet fit perfectly.

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Old enough to know better....
Young enough to try it again